20-year-old Marc Marquez has become the youngest ever MotoGP World Champion and the first rookie to take the title since Kenny Roberts in 1978.

Marquez was calm under pressure, settling for a third-place finish behind title rival Jorge Lorenzo and teammate Dani Pedrosa. It appeared the youngster had the bigger picture in mind, avoiding close combat throughout the race to win the title by a margin of four points.

“It’s a dream come true, maybe too early because I didn’t expect it in the first season in MotoGP,” said Marquez. “I cannot explain what I feel. To do it in front of all our fans, to fight with Jorge and Dani – two of the best riders in MotoGP.”

Kimi Raikkonen will miss the final two races in 2013. (Photo: Getty Images)

Kimi Raikkonen will miss the US and Brazilian GPs due to surgery on the back problem that reappeared over the Singapore GP weekend.

Finnish paper Turun Sanomat revealed today that the Lotus driver has opted not to compromise preparations for his return to Ferrari in 2014.

“Kimi will travel to Salzburg on Thursday and the operation will be carried out Thursday or possibly Friday,” his manager Steve Robertson told FOX Sports.com. “The doctor treating Kimi has already worked on Kimi’s back issue in the past. Having had cortisone injections in the back already this year and due to the discomfort of being in continuous pain it was felt there is no alternative to delay the operation.”

Jorge Lorenzo has topped the Warm-Up session ahead of the season-deciding GP Generali de la Comunitat Valenciana. The reigning World Champion, who will start this afternoon’s race from second place, led championship leader and pole-sitter Marc Marquez.

Sunday will mark the first last-race MotoGP title decider since Nicky Hayden claimed the world crown in 2006. On this occasion, rookie Marquez – aiming to become the youngest-ever premier class title winner – leads Lorenzo by 13 points.